Hi Robert
This is the article I was looking for  
   Touch lamp problems

Personally, I think touch lamps are one of the dumber uses of technology
to appear on this planet but that is just my opinion :-).

These are susceptible to damage from voltage surges or just plain old
random
failures.  In addition, the current surge that often results at the
instant
an incandescent bulb burns out (the bright flash) may blow the thyristor
in
the electronics module.

If the lamp is stuck on, the thyristor is probably shorted.  The
specific
part can be replaced but to be sure it is bad, some testing will be
needed
and it is probably soldered in place.  However, if you have repaired an
ordinary lamp, you will be able to replace the entire module fairly
easily.

If the lamp is stuck off, there could be a bad connection or bad bulb,
or
the electronics module is defective.  Again, replacement is
straightforward.

Erratic problems could be due to bad connections, dried up electrolytic
capacitors (especially if the electronics module is near the hot bulb),
or
even external E/M interference (e.g., a dimmer or vacuum cleaner on the
same
circuit).

Some problems are of the following type:

"I have 2 touch lamps in the bed room and they are both plugged in to
the
same receptacle.  Every once in a while the lamps come on by themselves
for no apparent reason.  Even more strange is that every so often just
one lamp turns on by itself."

(From: Tim Moore ([EMAIL PROTECTED])).

These use a MOSFET type circuit to switch the lamps on and off. The
circuit
is attached to the metal in the lamp base. When you touch it the
impedance
changes ever so minutely but enough to change the MOSFET from off to on
and visa versa. My wife could never get our lamps to switch, she often
had to blow on her hand first to get it moist so it would make better
contact. Here is part of the problem. It takes a certain amount of
signal from the lamp base to switch the circuit. Electronic parts all
have acceptable ranges of operation and when put into identical circuits
they sometimes perform differently. One circuit might need a good hard
touch while the other might need only a slight touch. Power surges would
often switch one of my lamps, although it didn't happen often. A strong
radio signal could do it too. The bottom line is that these lamps are
not rocket science and can't be counted on as 100% reliable. Sorry,
that's the truth. You give up a little to get the convenience of just
having to touch them. I ended up removing mine - an electrical storm
wiped one out and wiped the other out a few years later.

  Touch lamps and RF interference

While many people swear by touch lamps, nearly as many swear at them
since in
addition to frequent failures (bulb burn-outs killing the triac, for
example),
they can also be tempermental, cycling through their brightness settings
and/or turning on or off due to static electricity, power line
transients
causing RFI, and stray pickup from the local ham rig.

(Portions from: John Evans - N0HJ ([EMAIL PROTECTED])).

Here is a fix my buddy, Ed, a fellow ham radio operator, has come up
with to solve this problem.

As usual it took 8 months and 10 minutes to fix.

Two parts: 1/4 watt, 1k Ohm resistor and 2.5 mH 1/2 watt size molded
coil.
Connect in-line with the touch wire.

I send 2 or more watts from my rig.  My son works the CB.

You'll find it on when you get home.

So the darn thing is an oscillator which changes frequency when you
touch it.
The circuit does the rest.  By adding the resistor/inductor pair, its
sensitivity is reduced and the problem disappears.

One more thing:  (Most important!), you won't hear interference FROM the
oscillator in the lamp anymore on your radio.

And don't open up the module inside the lamp base, you are wasting your
time
there, and adding more work to glue the module back together.

Just Choke off the sense wire with the resistor and 2.5 mH choke.
You'll be
fine.

**********************************************************************
This message and its attachments may contain legally
privileged or confidential information. If you are not the
intended recipient, you must not disclose or use the
information contained in it. If you have received this e-mail
in error, please notify the sender immediately by return
e-mail and delete the e-mail.

Any content of this message and its attachments which
does not relate to the official business of Eraring Energy
must be taken not to have been sent or endorsed by
Eraring Energy. No warranty is made that the e-mail or
attachment(s) are free from computer virus or other defect.
**********************************************************************



[Non-text portions of this message have been removed]



To listen to the show archives go to link
 http://acbradio.org/handyman.html
or
ftp://ftp.acbradio.org/acbradio-archives/handyman/

The Pod Cast address for the Blind Handy Man Show is.
http://www.acbradio.org/news/xml/podcast.php?pgm=saturday

The Pod Cast address for the Cooking In The Dark Show is.
http://www.gcast.com/u/cookingindark/main.xml

Visit The New Blind Handy Man Files Page To Review Contributions From Various 
List Members At The Following Address:
http://www.jaws-users.com/handyman/
Visit the new archives page at the following address
http://www.mail-archive.com/blindhandyman@yahoogroups.com/  
For a complete list of email commands pertaining to the Blind Handy Man list 
just send a blank message to:
[EMAIL PROTECTED] 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/blindhandyman/

<*> To unsubscribe from this group, send an email to:
    [EMAIL PROTECTED]

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/
 


Reply via email to